Efficient propulsion of watercraft by means of one or more sets of oars requires manipulation of the blade portion of the oar so that a maximum amount of thrust is generated when the blade is in the water, and a minimum amount of drag results when the blade leaves the water. This is particularly true in competitive rowing which utilizes a stroke and recovery method which is designed to produce optimum thrust and minimum drag. As the blade is propelled through the water by the stroke of the oarsman, the blade is maintained at an angle generally perpendicular to the surface of the water. In preparation for the recovery, where the blade travels forward out of the water, the blade is rotated or feathered to occupy a position where it is generally parallel to the surface of the water. This feathering is achieved by rotating the blade to a horizontal location by rotation of the wrist as the blade is raised clear of the water. After completion of the recovery and in preparation for entry of the blade back into the water, the blade is again rotated or squared so that it occupies a vertical position.
In order to permit an oarsman to face the direction in which the boat is traveling, conventional apparatus have been disclosed for connecting an oar handle to an oar blade so that as the handle is moved in a longitudinal direction, such as for example, in a rearward direction, the is blade moved in the corresponding direction. Likewise, if the handle is moved in a forward direction, the blade is caused to move in the corresponding forward direction. These apparatus typically include a pair of adjacent drum members, one of which is connected to the oar handle, and the other of which is connected to the oar blade. These drums are typically mounted upon the gunwhale of a boat, and are interconnected by belts, chains, straps, or the like. These driving belts form an S-like configuration when the belts are typically mounted one above the other, and attached at their opposite ends to the respective drums. The belts are connected to the drums in a manner that a driving force from the oar handle is transmitted to its associated drum which in turn transmits a rotating driving force to the adjacent drum thereby moving the oar blade in a corresponding forward or rearward direction. Conventional oar transmission members of this configuration are disclosed in U.S. patents such as U.S. Pat. No. 107,669 by Dann; U.S. Pat. No. 195,778 by Wall; U.S. Pat. No. 284,984 by Schunk; U.S. Pat. No. 494,948 by Boardman; U.S. Pat. No. 538,081 by McFarland; U.S. Pat. No. 691,080 by Shedd; U.S. Pat. No. 788,884 by Buff; U.S. Pat. No. 808,720 by Buff; and U.S. Pat. No. 2,466,351 by Ankarlo.
Although the above-identified patents disclose transmission mechanisms for allowing a boat to be propelled by one or more oars in a forward facing direction, none of the patents disclose mechanisms to permit the oars to be feathered and/or squared as discussed previously.
In U.S. Pat. No. 1,034,462 by Johnson, there is disclosed a bow facing oar having a handle portion joined to a paddle portion by a universal joint. When the oar is used for a propulsion stroke, the rearward movement of the handle causes a corresponding movement of the oar blade. The universal joint allows the oar blade to be feathered or squared in correspondence with a rotation of the oar handle.